1. Field of the Invention
This invention relates to platform cooling of a turbomachinery vane or blade and more particularly to such cooling utilizing impingement cooling air jets impinging against the platform surface and means for isolating the impingement jet area from the main cooling flow stream so that the impingement jets are not canted or otherwise adversely affected by cooling air cross-flow.
2. Description of the Prior Art
In the vane or blade platform cooling art, many attempts have been made to adequately cool the platforms of vanes or blades, which are subjected to ever increasing temperatures as the power generated by turbomachinery increases with technological advances. Bluck U.S. Pat. No. 3,066,910 passes coolant through passages in the blade platform but this is a utilization of convection cooling only. Howard U.S. Pat. No. 3,527,543 discharges cooling air along the surface of a vane platform but this teaching utilizes film cooling only. French Pat. No. 1,214,618, which was published on Apr. 11, 1960, passes cooling air through passages adjacent the vane platform but this is a utilization of convection cooling only. Other patents such as U.S. Pat. Nos. 3,656,863; 3,318,573; 3,290,004; 2,828,940; 3,446,480; 3,446,482; and 3,446,481 all attempt to cool vane or blade platforms but none use the structure and combination of cooling principles taught herein.